When is the best time to plant?

Researchers from Sydney’s Institute of Agriculture at the University of Sydney have identified key time periods for planting crops to avoid the harmful effects of extreme climate events.

Dr. Qunying Luo, Dr Richard Trethowan, Dr Daniel Tan used crop modelling software APSIM (Agricultural Production System Simulator) and in-field validation to see how frost, heat stress and rainfall, seen at different points in the growing season, impact yields. This method allowed them to identify the optimal time for sowing. The study analysed theoretical yields for 20 one-week intervals between 1 April to 12 August over a 50-year period from 1957. Suntop and Gregory cultivars were used for Narrabri, and Mace for Roseworthy and Merredin.

Ultimately, the researchers found that the optimal sowing time that maximises wheat yield is 6-20 May at Narrabri, 13-27 May at Roseworthy, and 15 April at Merredin. As these regions represent major growing regions in Australia, the findings can be extrapolated to geographically similar locations. This optimal time for sowing will allow farmers to plant with a lower risk of frost damage at the beginning of the season, a lower risk of heat stress nearing the end of the growing season, and season optimal soil moisture.

These findings provide important and specific information for wheat growers about the management of extreme climatic event risk on farm. Qunying Luo, lead researcher on the project, felt that this research would be useful for farmers in the identified regions. She stated, “Wheat growers will find these new findings incredibly helpful for guiding farm practices. They will be able to see this translate into a more profitable crop.”

Luo also felt that this type of study could be replicated with a variety of crops, cultivars and locations to improve its generalizability and further its impacts to help farmers make the most informed management decisions.

As weather and extreme climate events become more common, this type of information will be essential for farmers as they seek to maximise their yields. Linking these decision-making tools with state-of-the-art seasonal and intra-seasonal climate forecast information will allow farmers to make the most appropriate sowing and harvesting decisions based on local weather and forecasts.

Although this study shows that risks can be lowered, weather is still a variable that cannot be controlled. We want know your opinions about managing risks and how to make farming sustainable in our survey here. You can also set up a time to chat with us here.